Elevator controls



R. A. BURGY ETAL ELEVATOR CONTROLS Feb. 27, 1962 Filed July 13, 1960 5Sheets-Sheet 1 r I I ,J HA) INC) INVENTORS RAYMOND AMBURGY PAUL F.DELAMATER ATTORNEYS Feb.

Filed July 13, 1960 R. A. BURGY ETAI.

ELEVATOR CONTROLS 3 Sheets-Sheet 2 ATTORNEYS United States PatentToledo, Ohio, assignors to Toledo Scale Corporation, Toledo, 01110, acorporation of Ohio Filed July 13, 1960, Ser. No. 42,635 It) Ciairns.(Cl. 187-29) This invention relates to the controls for a group ofelevators operating under a common control system and more particularlyto those aspects of the controls involving the dispatching of elevatorcars from dispatching termlnals in a given direction and the dispositionof cars arrlving at those dispatching terminals from landings displacedtherefrom in a direction opposite said given direcion.

The following description will deal primarily with the disposition ofcars which have served a basement landing below a lower dispatchinglanding from which cars are dispatched upward. However, it is to beunderstood that the control functions and equipment for performing thosefunctions disclosed herein are applicable toother than basement landingsas where the dispatching fioor is near the upper limit of travel of theelevator cars and there are landings above that upper dispatchingterminal from which cars will arrive. Similarly, while only a singlefloor beyond the dispatching terminal is discussed below it is to beunderstood that the features embodied herein might be applied where aplurality of such floors exist as where there are a multiplicity oflandings below a lower dispatching floor.

It is common practice in elevator systems wherein a plurality of carsoperate in an interrelated manner under the influence of a mastercontrol to stop the cars automatically at an intermediate landing, andunder ordinary circumstances reverse those cars at this stop anddispatch them therefrom in the opposite direction from which theyarrived. At a lower dispatching terminal descending cars are ordinarilystopped in the absence of calls either in the cars or at the landingsfor the landings below the lower dispatching terminal. Upon stoppingthey are reversed for upward travel and are thereafter dispatched upwardin some organized manneras on a time interval basis, a space intervalbasis, a call requirement basis or a combination of these bases.

When calls are registered for service to landings beyond the dispatchinglanding in the direction opposite normal dispatching, cars are enabledto serve those landings and when assigned to such service areeffectively removed from the group operation thereby diminishing theservice alforded by the group to a substantial degree. When a car hastraveled to a landing beyond the dispatching landing and is conditionedto return toward the dispatching landing, it can be treated in a numberof ways. in the past such cars have been caused to stop at thedispatching landing and then to travel beyond the dispatching landingWithout being introduced into the dispatching sequence and groupoperation. They have also been caused to pass the dispatching landingonly if a call is registered in the car requiring its service beyondthat landing in the dispatching direction. In the patent application ofRaymond A. Burgy, Serial No. 832,772 filed August 10, 1959, for ElevatorControls, a system is shown wherein a car traveling from a basementlanding to a lower dispatching landing stops at that lower dispatchinglanding and enters the dispatching sequence if a vacancy occurs in theload status for cars at the dispatching terminal during the stoppinginterval of that car, that car entering the load status and being thenext to be dispatched from the dispatching floor. Each of thesetechniques has been aimed toward a compromise wherein servicerequirements imposed by loads received at landings beyond thedispatching floor are met expe- 3,022,864 Patented Feb. 27, 1362 iceditiously yet the car serving those loads is returned to group serviceas rapidly as possible with as little disruption of the group operationas possible.

The present invention involves an improvement in the distribution ofelevator cars serving dispatching terminals and landings beyond thosedispatching terminals such as to minimize the detrimental effects ofservice to landings beyond on the regular operation of the system. Itsobjects are to improve elevator service, to expedite service for loadsimposed upon elevator cars at landings beyond dispatching floors, tominimize the interval cars serving landings beyond dispatching floorsare unavailable for normal group dispatching and to avoid unnecessarytravel of cars without diminishing the service aitorded.

in accordance with these objects, one feature of this invention residesin expediting the dispatch of a car standing at a dispatching terminalconditioned for loading upon the arrival at that terminal of a cartraveling from a landing beyond the dispatching terminal. A subsidiaryfeature involves substituting the arriving car in the load status sothat it is the next car at the dispatching terminal to be conditionedfor loading and to be dispatched by the normal dispatching operation.

Another feature of this invention comprises substituting a car arrivingfrom a landing beyond the dispatching terminal into the load status fora car standing at the dispatching terminal upon which no demand forservice has been imposed. This feature is particularly applicable tosystems wherein the cars are permitted to become inactive and accumulateat the dispatching terminals when service requirements diminish, asduring the night hours. At such times a car will be assigned a loadstatus and maintain that status in accordance with certain operatingschemes even though it is not dispatched from the terminal. A cararriving from a floor beyond will release the load car from its statusand substitute itself so that an active car, upon which it is morelikely service demand will be imposed, enters the load status and, ifsuch demand is imposed, in due course is dispatched from the dispatchingterminal.

The above and additional objects and features of this invention will bemore fully appreciated from the following detailcd description when readwith reference to the accompanying drawings, wherein:

FIG. I is a schematic portrayal of a three-car elevator system having alower dispatching landing, a plurality of landings above the lowerdispatching landing and a basement below the lower dispatching landingand being controlled by a master supervisory control;

FIG. H is an across the line diagram of a portion of the controlcircuits actuated by the positioning of individual cars along theirpaths of travel utilized in this invention;

FIG. III is an across the line diagram of circuits common to the severalcars of the group which function according to this invention; and

FIG. IV is an across the line diagram of a dispatching control circuitfor the group.

Only those portions of an elevator system directly involved in thecontrols of this invention are disclosed herein, it being understoodthat this invention is applicable to many types of systems whereindifierent types of individual car controls and system controls areemployed. It is advantageous to arrange the cars so that they can beoperated either with or without attendants and will run when operatingwithout attendants in response to the registration of calls at landingsor in the cars. The system should be provided with a main dispatchingterminal near the lower limits of car travel at which cars are requiredto stop when they descend to that terminal and have no demand imposedupon them requiring them to travel below that terminal. If a demand fortravel beassess a low the main terminal is registered the cars caneither be arranged to stop at the terminal and then proceed to respondto that demand or can proceed directly to respond to that demand withoutstopping unless a call is registered which requires a stop at the mainterminal. One system of car control including a supervisory control fora group of elevators is disclosed in R. A. Burgy patent application,Serial No. 808,290 which was filed March 30, 1959, for ElevatorControls. Reference is made to that disclosure for a control asillustrative of one practical system which can incorporate the circuitsdepicted herein.

FIG. I represents a bank of three cars, A, B, and C. Throughout thespecification and drawings those elements individual to the cars havebeen identified therewith by the sufiix letter designating the carenclosed in parentheses. Thus, CUPHA) is the lower terminal selectionrelay for car A and contacts similarly designated are the contacts ofthat relay for that car.

The illustrated system can be considered to constitute a bottom floordesignated a basement B, a first floor above the basement which will beconsidered the main terminal or lower dispatching terminal 1, a topfloor T which can be an upper dispatching terminal and a plurality offloors intermediate the main terminal and the upper dispatchingterminal. It will be understood that the invention is applicable to abank of elevators containing any number of cars and serving any numberof floors and that the system of three cars has been chosen forillustrative purposes only.

The elements individually associated with car A include a car 11suspended by hoisting cables 12 trained over a traction sheave TS;driven by a lifting motor 14 which may be of any convenient type butordinarily is arranged for variable voltage control as in the well-knownWard-Leonard type system. Coupled to the opposite end of the liftingcable 12 is a counterweight 15. A floor selector 16 is associated withthe car to establish appropriate circuits for the car position at anyinstant. This 'fioor selector can be of the commutating type including atwo coordinate system of contact segments on a panel where contacts forgiven functions are oriented in vertical lanes and the several contactsof the circuits performing difierent functions for each floor aregenerally aligned in rows transverse of those lanes. A crosshead (notshown) sustaining a number of commutating brushes is mounted to becarried along the contacts parallel to the lanes either in synchronismwith the car or suitably in advance of the running car and insynchronisrn with the stopped car, depending on the nature of theselecting machine and controls. While. the contacts of the floorselector illustrated in the circuits to be described are mechanicallycommutated by a crosshead which is advanced with respect to the carwhile it is running, it is to be appreciated that controls employingother forms of mechanical commutators well known to the art can beadapted to this invention and that other forms of selector devices suchas relay selectors also lend themselves to utilization of the featuresof this invention.

Each of the cars A to C have individual controls including the floorselectors 16 (A) through 16(C) and supplemental equipment apart fromthose floor selectors. All of these car controls are integrated into asystem insuring interrelated operation of the cars by means of a groupsupervisory control, schematically represented by the rectangle l7,interlinked to the door selectors by the cable 18. The group supervisorycontrol 17 can include means for establishing various programs ofoperation in accordance with manual selecting devices, call controldevices, or means sensing conditions in the elevator system. it can alsoinclude dispatch timers or devices which dispatch on other than a timebasis for certain aspects of the invention and means for generallycontrolling the operating pattern of individual cars and the group evento the extent of removing cars from service or introducing cars intoservice.

The invention will be considered as applied to an auto matic elevatorsystem wherein no attendants are required on the cars and the passengersdirect the car operation by indicating their demands for service fromhall call registering means i? located at each of the several floors andincluding down hall call means at the top through the first fioor and uphall call registering means at the basement through the door adjacentthe top floor. These call registering means can be common to all cars inthe bank and are schematically represented as interconnected to theseveral cars through the group supervisory control rectangle 17 by meansof cable 29. Passengers within the cars indicate their desireddestination by the registra tion of calls upon call registering meanstherein (not shown) which can be individual to the several hours servedby the cars.

A system of this nature can readily be transferred to operator controlwherein prospective passengers employ the landing buttons to registertheir calls to stop the car automatically and the operator employs thecar buttons to set up the stops for the car, the primary function of theoperator being to direct the passengers and to actuate the closingoperation of the elevator doors inasmuch as the doors will openautomatically upon stopping as in a sy tem operating without attendants.

in order to facilitate an understanding of the circuits illustrated inFIGS. II through IV an alphabetical listing of the symbols for therelays and contacts utilized is presented below together with a shortdescription of those relays and the location, if shown, of theiractuating coils. These relays and all other circuit elements are shownin across the line diagrams. The relay contacts, therefore, are oftenlocated remote from their actuating coils. In order to correlate thelocation of the actuating coils and contacts, a marginal key has beenemployed with each of the circuit diagrams. With this key each diagramhas been divided into horizontal bands which are identified with linenumbers in the right hand margin. Relay symbols are located in themargin to the right of the line numbers and in horizontal alignment withthe coil. positions. The location of each contact actuated by a relaycoil is set forth to the right of the relay symbol by the numeral of theline upon which it appears. The numerals designating the location ofback contacts, those which are normally closed when the relay isdeenergized and are opened when it is energized, are underlined in thekey to distinguish them from front contacts, those which are closed uponthe energization of the coil with which they are associated. Thus,- theup load relay for car A, CUL(A), appearing on line 55 has front contactsat lines 34, 55, 56 and 66 and back contacts at lines 25, 31, 42, and51, as signified by the numerals in the margin of FIG. 1V at line 55.The relay and switch symbols illus trated in the diagrams are asfollows:

Designation Above main floor relay Bnsarncntrun relay... Up 1r run relayC112 call above reldyfciws A to C l)oor cl "inc. rcla Up dispatch relay,cars A to 0. Up load relay, cars A to 6.-

Load ear reset. relay Lower terminal selection relay, cars A to CUD(A)to (0) OUL(A) to (C) OULR CUNLK) to (0)."

Up illispatoh timer hold relay.

d .patoh tit. r in. crval Up scheduling relay 1 Bottom dispatchinc floorrel Auxiliary bottom dispatching n00. relay Master door reclusint! relayUo rotary disaatch selector siritch I-lall call indication relay. Upcall indication. relay Up encrator field re Load car :eq'iencc relaDescription of FIG. 11

FIG. II illustrates certain of the circuits operated by the floorselector of a typical car. All circuits are supplied from a suitablesource of alternating current connected across the power leads GN andEN. These circuits are actuated by the elfective travel of the car whichcauses the crosshead carried brush 91 to be engaged with the floorselector contact segment 92, 93 or 94 when the car effectively reachespositions in its travel corresponding to the position of those contactsin the floor selector lane. The term effective car position is employedherein to designate the position at which the car can respond to signalsas determined by the crosshead position, for example. Thus a car mightbe a floor or more away from a landing when its crosshead reaches aposition on the selector corresponding to the landing in a system usingan advanced crosshead. When a car runs upward from the lower dispatchingfloor so that its up generator field relay is energized to close contactUF at 21 and brush )1 engages contact 94 at 21, relay BUR is energizedmomentarily to actuate certain controls including the reset of thedispatch timer as will be described below. The arrowhead lead 95 extendsto the contacts of other floor selectors (not shown) corresponding tocontact 94 through up generator field relay contacts (not shown) ofthose other cars such that departure of any car from the lowerdispatching terminal upward will actuate relay BUR.

When a car is stopped at the lower terminal, its MG relay at 22 isenergized through the engagement of brush 91 with floor selector contact93. This relay is of primary significance in the dispatch controloperations as will be discussed. Auxiliary lower dispatch terminal relayMGX at 23 is energized with relay MG until the car standing at a lowerterminal is issued a dispatch signal and its CUD relay is energized toopen contact CUD at 23. Relay MGX functions in the dispatch circuitsprincipally in resetting certain of the relays.

Basement run relay BR at 24 is energized as the car effectively reachesthe basement landing. Thus when the crosshead, moving in advance of thecar, moves brush 91 into contact with contact segment 92, relay BR ispulled in. This relay seals itself in through the circuit at 25including contact BR, up load relay back contact CUL and above mainfloor relay back contact AMF. Therefore, relay BR remains energizeduntil the car either travels above the lower dispatching landing to opencontact AMF of a relay which is energized while the car is effectivelyabove the lower dispatching landing or until the car enters the up loadstatus and opens its back contact CUL.

Description of FIG. III

Load car reset relay CULR at 32 responds to the arrival from thebasement of a car and upon responding removes the then current up loadcar from its up load status creating a vacancy in that status which canbe filled by the car arriving from the basement. If a car is in loadstatus, relay XT is energized to close its contact at 32 and enable CULRto be energized. For example, the arrival of car A from the basementwould energize CULR through the circuit at 31 inasmuch as car Asbasement run relay would close contact BR(A), its presence at the maindispatching terminal would close its contact MGX(A), and until it entersthe up load status contact CUL(A) would be closed. The present systemcontemplates sustaining a car in up load status even when it is not atthe main dispatch terminal when the system is providing a reduced levelof service, as at night. Thus, when operated in that manner a loadstatus car can run to the basement. Such a car should not operate theload car reset relay CULR, accordingly, its CUL contacts are opened at25 to bar energization of ER under these circumstances and prevent suchoperation. In this manner a load car returning from the basement retainsits load status on the right program. Energization of CULR closes itscontact at 39 to issue an up dispatch signal to a load car as will bedescribed. Other CULR contacts at 55, 56, 6t and 64 are opened torelease the car conditioned for loading, one in up load status, fromthat status. These circuits are efiective where the doors of the loadcar are closed and no call is registered requiring the dispatch of thereleased car or where the system is conditioned to retain up load statuson a car away from the main terminal.

Up dispatch reset relay DFUL at 35 is energized when any car in the bankis in the up load status to close contact CUL at 34 through 36 for thatcar. DFUL enters into the reset sequence for up scheduling relay KU aswill be described with respect to the circuit at line 41 and completes aportion of the energizing circuit for relay KU in conjunction with loadcar reset relay CULR at line 39.

Load car sequence relay XT is of the rapid pull-in slow dropout type andis energized with relay DFUL through the up load relay contacts at 34through 36 of any car in up load status. It controls contacts in the upload relay circuits at 54 through 65 to afford a preference inintroducing basement run cars into up load status over cars which wereselected and standing at the lower dispatching floors with their lowerterminal selection relay CUN energized. XT also controls up dispatchreset relay DFUT at 37 to control the reset of the dispatching equipmentand particularly of scheduling relay KU to be described. By opening itsXT contact at 32 when no car is in the load status relay CULR isprevented from operating and proper sequencing of operation is assured.No reset of a load car can occur in the absence of a load car; henceload car reset relay need not operate at this time. The car arrivingfrom the basement encountering a vacancy in load status enters thatstatus immediately as will be described.

Up scheduling relay KU at 39 when energized closes a contact at 66 toenergize the up dispatching relay of a car in the up load status wherebythat car is started away from the main terminal. A number of energizingcircuits and resetting circuits are provided for up scheduling relay KU.Timed dispatching is efiected through the closure of contact J3 at 38upon energization of the third up dispatch timer interval relay (notshown) provided a load car is available and a call is in registration towhich that load car can respond so that up dispatch timer holding relayDFU is decnergized and its back contact at 38 is closed. KU can also beenergized in accordance with this invention by the arrival from thebasement of a car which energizes load car reset relay CULR as describedand closes contact CULR at 39, provided another car is in load statusand has energized the up dispatch reset relay DEUL to close its contactat 39 and provided a call for travel above is in registration todeenergize relay UC, in a manner to be described, and close its backcontact at line 39.

As disclosed in detail in the aforenoted Burgy application, Serial No.808,290, up scheduling relay KU resets the dispatch timer controllingthe operation of dispatch interval relays J2 and I3 in addition toissuing a dispatch signal to the car currently in up load status. Upondeparture of a car from the main terminal relay BUR at 21 is energizedto close contact BUR at 49, and again reset relay KU and the dispatchtimer. Relay KU is of the magnetic latch type wherein a pull-in coil isenergized through the circuit including the leads extending from thesymbol horizontally and a reset coil is connected across the verticallead and the right hand horizontal lead. Energization of the pull-incoil generates sufiicient flux to hold the relay energized even afterthat circuit is opened and until the reset coil is energized to generatean opposing or dropout flux. The closure of contact BUR energizes thisreset circuit. Relay KU is also reset shortly after the dispatch signalis issued to a load car through the circuit at 41. Upon issuance of adispatch 7 signal, relay MGX is deenergized by the opening of backcontact CUD at 23. This opens contact MGX for the up load car at lines51 through 53 to drop out the cars up load relay CUL, thereby openingthe energizing circuits for DFUL and X? at lines 34 through 36. DFULdrops out immediately closing its contact at line 42. However, relay X1has a delayed dropout and therefore maintains its contact at 3'7 closedto hold DFUT ener gized and therefore contact DFUT at 41 closed. Thismaintains continuity of a reset circuit at line 411 for the relay KU.Shortly after the dropout of iii], relay times out opening its contactat 37 and dropping relay DFUT to open that contact at it after anotherdropout interval. Thus, the reset circuit for relay KU is opened and KUis enabled for the dispatching of additional cars.

Dispatch timer holding relays DFUA at 42. and DFU at prevent thedispatch of a car in the absence of a call which it is capable ofserving and detent the dispatcher when it is only partially timed out.These relays are enabled when the second up dispatch timer intervalrelay I2 is energized to close its contact at 42. If no up load car isavailable at this time, the series of normally closed CUL contacts at 42are closed to complete a circuit energizing relay DFUA. This relay stopsthe timing operation or" the timer while holding it partially timed outwith relay J2 energized. It closes a contact at 43 to energize relayDFU. Upon a car entering the up load status and opening both its CUL andMGX contacts, relay DFUA is deenergized and the dispatch timer ispermittcd to continue timing its dispatching interval. DFU isdeenergized provided the energizing circuit through contact UC at 44 isopen indicating that a call is registered above the lower dispatchingdoor which can be served by the current load car.

Relay UC appears at line 45. When it is energized it indicates anabsence of a call which the load car is capable of serving. Uponregistration of any call which the loadrcar can serve, relay UC isdeenergized. A landing call when registered deenergizes relay SS to dropout its contact at 45. A car call above the load car drops relay UC byopening its contact CB such that the parallel circuit provided by backcontacts CB at 46 and parallel back contact CUL at are both open forthat car.

Description of FIG. IV

The circuits for dispatching cars from the main terminal are disclosedin FIG. IV. They include lower terminal selection relays CUN for theindividual cars, only one of which is energized at any given time toindicate that that car is conditioned as the next to be conditioned fordeparture from the lower dispatching terminal. While all of the detailsof the lower terminal car selection circuits are not shown in thediagrams, the purpose of these relays is to efi'ect a selectiondetermining which car will depart either by assignment to an up loadstatus energizing its CUL relay or by assignment for travel to a landingbelow the lower dispatching terminal where such travel is required.

The up load relays CUL for the individual cars are energizedindividually to introduce a car into the up load status and maintain itin that status. Whenso conditioned, a car receives passengers and isenabled to receive a dispatching signal when the system sensesconditions warranting the dispatch of the car. This dispatching signalis issued through the energization of up dispatching relay CUD for thatcar.

The presence of a car at the lower dispatching floor energizes its relayMGX to close its contact at lines 57., 52 or 53. If the car has notarrived from the basement, its BR hack contact at lines 53, 52 or 53- isalso closed and if it is not upload status, its CUL contact at one ofthose lines is closed. Thus its lower terminal selection relay circuitis enabled and can be completed by the operation of up rotary dispatchselection switch contact .21 contact, energizing relay CUIMA) at 51.CUNQ-l) closes its contact at line 55 to enable the energization of theup load relay for car A provided there is a vacancy in the up loadstatus.

Assuming that car B is currently in the up load status and has itsCULGB) relay at 59 energized, and relay DFUT is energized as describedto open its contact at 63, the closing of contact CUN(A) at 55 has noeffect due to the open DFUT contact at 63. When car B is dispatched andits CUL(B) relay is deencrgizcd to ultimately drop out DFUT and relayXT, a circuit is completed for relay CUL(A) as follows: Contact MGX(A)at 51, lead 95, coil CUL(A), contact CUN(A) at 55, lead 96, contact DFUTat 63, contact XT at 62 to lead BN. CUL(A) then pulls in to first closeits contact CUL(A) at 56 and establish a sealing circuit from MGX(A),lead 95, contact CUL(A), back contacts CULR at 556 and CLHA) at 57,leads 9'! and 98 to lead BN. It also enables an energizing circuit forup dispatch relay CUD(A) by closing a contact at 66. In addition, itactuates a number of auxiliary relays shown in FIG. Ill, opening CUL(A)contact at 31, with no efi'ect at this time, closing contact CUL(A) at34 to energize DFUL and X1", opening contact CUL at line 25 with noeilect at this time inasmuch as it was assumed that the car did notarrive from the basement and relay ER is deenergized, opening contactCUL(A) at 42 to prevent the energization of relay DFUA when contact 12is closed, opening contact CUL(A) at to open one portion of theenergizing circuit for up call relay UC whereby that relay will bedropped upon the energization of a car call in car A to open contactCB(A) at 46, opening contact CUL(A) at 51 to deenergize relay CUN(A)enabling another car to be selected by operation of the rotary dispatchselector RSU and closing a contact CUL(A) at 55 with no eifect at thistime. Since the cars MG relay is energized to closed contact MG(A) at66, upon the operation of relay KU closing its contact at 66, car A isdispatched by operation of relay CUD(A) through the circuit MG(A),CUD(A), CUL(A) and KU, all at 66.

At night when the trafiic is light and the lifting motors of theelevator cars are shut down, it is desirable to confine service to onecar if this can be done without detracting from the service provided. Inorder to do this, a load car is enabled to maintain its load status eventhough it is away from the fioor inasmuch as it is the only car with itsmotor operating. The circuit at 55 and 56 maintains this load status byholding the cars CUL relay energized. Thus as described, ordinarily theissuance of a dispatch signal by energization of relay CUD drops outrelay MGX at 23 to open its contact at 51 and drop the up load relayCUL. However, the circuit at 55 and 56 establishes a seal around thisopen MGX contact on the night or low intensity service. On nightservice, the doors of the elevator cars are reclosed when they arrive atthe main terminal and master door reclosin" relay RCL, not shown, isenergized to close. its contact at 55. A car which is required to travelfrom the main terminal maintains its load status in the absence of ahall call through closed contact 55 at 55', closed contact RCL, closedcontact CULR and closed contact CUL at 5'5, or 63 depending on which caris in the load status. if a hall call is in registration and relay ESdeenergized to open its contact 55, the load status will be maintainedon the car while it is away from the terminal only until the detentpoint is reached by the dispatch timer to close contact J2 at 42 toenergize relay DFUA. Relay DFUA is energized at this time even though acar is in the up load status since the load cars MGX contact at 43 isclosed while it is away from the terminal to bypass its open CUL contactat 42.

Operation The above described equipment responds to the arrival of a carfrom the basement by removing the car then in the up load status fromthat status, placing the newly arrived car in that status in preferenceto any others which might be available for such conditioning, andenabling that car to be dispatched if warranted. When a car is removedfrom theup load status, it is dispatched upward if a call is registeredto which it can respond. However, if no calls are registered for thatcar under certain operating conditions, it is merely removed from loadstatus without dispatching.

In considering the operation, first assume that all cars are reasonablyactive as in a normal working day, a car arrives from the basement andthere is no car at the lower terminal in the up load status. Under thesecircumstances, no CUL relay is energized and relays DFUT and XI aredeenergized. The car arriving from the basement has its BR relayenergized so that contacts BR at 51, 52 or 53 are open for that car andBR contacts at 54, 58 or 62 are closed. As relay MGX for the car isenergized, its relay CUL is pulled in inasmuch as a circuit is completedthrough contacts MGX, BR and XT between leads GN and EN. When the carenters the load status, it can be dispatched in the normal manner assoon as the dispatching interval expires provided a call is registeredto which it can respond. In this regard it should be recognized thatwhile the present system is arranged to operate on call, that is, torelease cars from the dispatching terminal only when a call is inregistration, the invention might be applied to a system Where cars aredispatched on regular time intervals without departing from its spirit.

If all cars are in operation under normal daytime service and a car isavailable at the dispatching terminal in load status with its CUL relayenergized at the time another car arrives from the basement with its BRrelay energized, relay CULR at 32 is pulled in to open its contact atline 56, 59 or 64 with no efiect provided the car doors are not reclosedand contact CLl at 57, 61 or 65 is closed. However, if the call is inregistration the load car is dispatched through the circuit energizingup scheduling relay KU at 39 including contacts DFUL which are closedsince the car is in load status, CULR closed by the arrival of the carfrom the basement, and back contact U-C indicating that a call is inregistration above the main terminal. The load car then advances intodispatched status with its dispatch relay CUD energized and its up loadrelay CUL deenergized. Basement run car fills this vacancy in the upload status. KU also resets the dispatch timer so that it initiates anew timing interval for the arriving car newly admitted to the up loadstatus. Upon the expiration of that dispatching interval, relay KU isenergized by the dispatch timing means through contact J3 and thatbasement car which was admitted to load status is dispatched by havingits CUD relay energized.

In both of the above examples, it should be noted that the presence of acar at the lower terminal with its CUN relay energized has no effect inintroducing that car into the up load status while a basement run car isavailable for such introduction because of the time sequencing of therelays XT and DFT. Thus XT drops out a suitable-dropout intervalfollowing the release of the up load car and initiates the dropout ofrelay DFUT. However, DFUT remains held in for the dropout intervalsuilieient for the load relay of the car arriving from the basement topull in under the influence of closed contact BR in the up load relaycircuit to lead 99 and holds contact DFUT at line 63 open preventing theCUN contact of the other car at the terminal connected to lead 96, frombeing etfective in actuating its up load relay.

If a car arrives from the basement when a load car is at the lowerterminal but no call is registered which can be served by the load caris registered during the time the basement run car is stopped at theterminal, the basement run car proceeds upward without entering the loadstatus and the load car continues to await a call for service. Underthese circumstances the basement run car stops for an intervaldetermined as for any other stop. -t is blocked from entering loadstatus since relay KU is prevented from operating by the energized callrelay UC which opens contact UC at 39 and cause contact DFU at 38 to beopen. The current load car is not dispatched and therefore no vacancyoccurs in the load status which can be filled by the basement run car.

As noted above, on night operation the cars tend to shut down, and inshutting down close their doors. Incidental to the closure of theindividual car doors, the door reclosing relays CLl (not shown)individual to the cars are energized to open the contacts for those carsat 57, 61 and 65. These contacts cooperate with the load car releaserelay to release a car in load status with its doors closed at the mainterminal from load status in response to the arrival of a car from thebasement. That car is released without being dispatched it no call isregistered to which it can respond and relay KU does not operate. Assumecar A is the load car at the lower dispatching floor with its doorsclosed, thus relay CUL(A) is energized through contacts MGX(A) at 51,contact CUL(A) and CULR at 56, and leads 97 and 98. Since the doors arereclosed, contact CL1(A) at 57 is open. If car B were to arrive from thebasement, its BR relay would be energized opening contact BR(B) at line52 to prevent the energization of CUN(B). Contact BR(B) at 58 wouldclose to enable with contact MGX(B) at 52 an energizing circuit for upload relay CUL(B) as soon as car A is released from the up load status.Car B energizes relay CULR through the circuit at line 32 includingcontacts BR(B), MGX(B), CUL(B) and XT. Relay CULR opens its contact atline 56 to drop out relay CUL(A) in view of the open CL1(A) contact at57. This drops out relay DFUL, and deenergizes relay XT which drops outafter a time to close its contact at 62. When the XT contact at 62closes CUL(B) is energized and car B enters the up load status and isdispatched if a call is registered at the end of the dispatch interval.

Under the conditions assumed car A is not dispatched unless a call isregistered to which it can respond. If a call is in registration towhich the load car can respond, relay UC is deenergized. Under thesecircumstances, KU is energized when CULR pulls in at 39 through contactDPUL, CULR and UC to send car A away from the lower dispatching terminalas a dispatched car. If, on the other hand, no hall call is registeredand no car call was registered incidental to an entry of a passengerprior to the closing of the doors for car A, car A remains at the lowerdispatching floor because relay KU is not energized. It is thus seenthat a car arriving from the basement at the main dispatching floor whenthe system is on reduced service will remove the load car from loaddispatching and dispatch that car only if its travel is required.

As noted the night service operation contemplated for this systemincludes maintenance of up load status on a car while it is located atother than a main dispatching floor through the holding circuit at line55 bypassing the MGX contacts at 151 through 153. If a car arrives atthe main dispatching terminal from the basement while the load car isaway from the floor, the load car relinquishes its status to this newlyarriving car. While the load car is away from the floor, door reclosingcontacts CLl at 57, 61 or 65 are closed to seal a circuit around contactCULR at -5, 69 or 64. However, the load cars seal circuit around its MGXcontact is opened at line 55 by the energization of CULR to open itscontact at 55. This breaks the seal circuit for the current load car andcreates the vacancy which is occupied by the car arriving from thebasement through the sequencing which closes contact XT to rendercontact BR at 54, 53 or as effective in pulling in the up load relay CULof that arriving car prior to contacts CUN at 54, 53 or 62 for any othercar. As in previous instances that car assumes load status with the sameeffect as any other and is dispatched in due course by the dispatchtimer provided a call is registered to which it can respond.

8n night service the load car may be sent to the basement. In thisinstance it is unnecessary for the load car reset relay CULR to operatewhen the load car returns from the basement to the main displatchingterminal in asmuch as it would merely remove and reintroduce that carinto the load status. Accordingly, if the load car is serving thebasement, back contact CUL at 25 is open to maintain the cars BR contactat 31, 32 or 33 open and CULR is disabled so that the resettingoperation does not occur.

In each instance when. a car ariving from the basement enters the loadstatus, it drops its basement run relay BR by opening contact CUL atline 25. This drops the up load reset relay CULR by opening contact BRat line 31 through 33. Thus the arriving cars CUL relay can be pulled inand sealed in to maintain it in the load status until it is dispatched.

It will be appreciated from the above that the arrival of a car from afloor beyond the dispatching terminal causes a car at that terminal inthe load status, that is conditioned to be loaded and then dispatched,to be dis patched expeditiously, if a call is registered to which it canrespond, creating a vacancy in that load status which is filled by thearriving'car in preference to all others. One exception to this mode ofoperation occurs on re duccd service Where there is no need to dispatchthe load car in which instance it'is merely removed from the load statusand replaced by the arriving car. Thus, the floor beyond servicedisrupts the dispatching system and the scheduling of cars a minimumamount. The system is returned to its normal mode of operation with fullcapacity as rapidly as possible. Passengers'entering a car at thebasement may be delayed by a somewhat extended stopping interval at themain landing when they seek to travel to landings above the terminal.However, this delay is limited to a maximum of one dispatch in'erval andimposes a minimum of inconvenience on those passengers. Further, thesystem is arranged to effectively utilize cars and cause them to runonly when it is necessary in the interest of serving existing calls.

It is to be appreciated that the above disclosure lends itself tomodification and incorporation systems other than those considered here.Accordingly, this disclosure is to be read as illustrative and not in alimiting sense and many modifications are recognized to be availablewithout departing from its spirit or scope.

Having ascribed the invention, we claim:

1; An elevator system comprising a plurality of cars serving dispatchinglanding, a plurality of landings displaced in given direction from saiddispatching landing and at least one landing beyond said dispatchinglanding in a second direction opposite said given direction, means tocondition cars for loading at said dispatching landing and meansresponsive to the travel of a car toward said dispatching landing onlyfrom said second direction for eleasing a conditioned car from saidconditioned state.

2. An elevator system comprising a plurality of cars serving adispatching landing, a plurality of landings displaced in a givendirection from said dispatching landing at least one-landing eyond saiddispatching land 12 ing in a' second direction opposite said givendirection, means to condition cars for loading at said dispatchinglanding and means responsive to the travel of a car toward saiddispatching landing only from said second direction for expediting thedispatch of said conditioned car.

3. An elevator system comprising a plurality of cars serving adispatching landing, a plurality of landings displaced in a givendirection from said dispatching landing and at least one landing beyondsaid dispatching landing a second direction opposite said givendirection, means to condition cars for loading at said dispatchinglanding, means sensing the travel of a car to said landing beyond, meansresponsive to the effective arrival of a car at said dispatching landingonly from said landing beyond and means actuated by the response of saidlast named means for releasing said conditioned car from saidconditioned state.

4. An elevator system comprising a plurality of cars serving adispatching landing, a plurality of landings displaced in a givendirection from said dispatching landing and at least one landing beyondsaid dispatching landing in a second direction opposite said givendirection, means to condition cars for loading at said dispatchinglanding, means responsive to the travel of a car to said dispatchinglanding only from said landing beyond said dispatching landin fordispatching said conditioned car, and means for conditioning said carfrom said landing beyond for loading at said dispatching landing.

5. An elevator system comprising a plurality of cars serving adispatching landing, a plurality of landings displaced in a givendirection from said dispatching landing and at least one landing beyondsaid dispatching landing in a second direction opposite said givendirection, means to condition cars for dispatching from said dispatchinglanding, means responsive to the travel of a car to said dispatchinglanding only from said landing beyond said dispatching landing fordispatching said conditioned car, and means for conditioning said carfrom said landing beyond for loading at said dispatching landing inpreference to any other car at said dispatching landing.

6. An elevator system comprising a plurality of cars serving adispatching landing, a plurality of landings displaced in a givendirection from said dispatching landing and at least one landing beyondsaid dispatching landing in a second direction opposite said givendirection, means to condition cars for loading at said dispatchinglanding, means responsive to travel of a car to said dispatching landingonly from said landing beyond said dispatching landing for releasingsaid conditioned car from said conditioned state and means forconditioning said car from said landing beyond for loading at saiddispatching landing in preference to any other car at said dispatchinglanding.

7. An elevator system comprising a plurality of cars serving adispatching landing, a plurality of landings displaced in a givendirection from said dispatching landing and at least one landing beyondsaid dispatching landing in a second direction opposite said givendirection, means to condition cars for loading at said dispatchinglanding, means to register calls for service by said cars, meansresponsive to a registered call which said conditioned car is capable ofserving and means enabled when said last named means is responsive andresponsive to the travel of a car toward said dispatching landing fromsaid second direction only for expediting the dispatch of a conditionedcar.

8. An elevator system comprising a plurality of cars serving adispatching landing, a plurality of landings spaced in a first directionfrom said dispatching landing and at least one landing spaced from saiddispatching landing in a second direction opposite said first direction,comprising means to condition a car at said dispatching landing as aload car which is next to be dispatched, means to maintain the status ofa car conditioned as a load car while it is spaced from said dispatchinglanding, and means responsive to the arrival of a car at saiddispatching landing only from said second direction for releasing theconditioned car from said load status.

9. An elevator system comprising a plurality of cars serving adispatching landing, a plurality of landings spaced in a first directionfrom said dispatching landing and at least one landing spaced from saiddispatching landing in a second direction opposite said first direction,

comprising means to condition a car at said dispatching landing as aload car which is next to be dispatched, means to maintain the status ofa car conditioned as a load car while it is spaced from said dispatchinglanding, and means responsive to the arrival of a car other than saidconditioned car at said dispatching landing only from said seconddirection for releasing the conditioned car from said load status.

10. An elevator system comprising a plurality of cars serving adispatching landing, a plurality of landings spaced in a first directionfrom said dispatching landing and at least one landing spaced from saiddispatching landing in a second direction opposite said first direction,comprising means to condition a car at said dispatching landing as aload car which is next to be dispatched, means to maintain the status ofa car conditioned as a load car While it is spaced from said dispatchinglanding, means responsive to the arrival of a car other than saidconditioned car at said dispatching landing only from said seconddirection for releasing the conditioned car from said load status andmeans for conditioning as a load car, said car which arrived at saiddispatching landing from a point spaced therefrom in said seconddirection in preference to any other car at said dispatching landing.

No references cited.

